1. Field of the Invention
The present invention relates to a latch device used for a cockpit door or the like provided between a cabin and a cockpit of an aircraft.
2. Description of the Related Art
FIG. 1 illustrates an outline of a cockpit door, and a cockpit door 1 is required to be held closed during flight and also to be unable to be easily opened/closed for a security reason. For this purpose, an electronic mechanism or the like is used so that a latch device 2 is electrically released by typing a password on a keypad 3.
In an aircraft, the inside is pressurized during flight and adjusted to an internal pressure higher than the atmospheric pressure.
However, if the pressure is reduced on a cockpit 4 side due to some reasons, a differential pressure is generated with respect to the pressure on a cabin 5 side. In order to let this differential pressure go, there is a need to reduce the pressure of the cabin 5 by opening the cockpit door 1 toward the cockpit 4 side.
The Japanese Patent Laid-Open Publication No. 2003-261098 relates to a latch device of a cockpit door of an aircraft proposed by the present applicant.
The latch device of the cockpit door of an aircraft comprises a handle provided on the cockpit side of a door panel, a handle unit having a bolt releasably engaged with a catch provided at a door frame by operation of the handle, and a bolt releasing mechanism for forcedly releasing the bolt from the catch upon detection of an air pressure inside a cabin when the air-pressure in a cockpit drops.
However, in the above latch device of the cockpit door of an aircraft, if some impact is applied to the cockpit door 1 from the cabin 5 side, a piston member of the bolt releasing mechanism is moved by inertia, and though there is no differential pressure generated, the bolt is unexpectedly released from the catch and the cockpit door 1 might be opened toward the cockpit 4 side.
An object of the present invention is to provide a latch device of a cockpit door of an aircraft which solves the above problem.